Method and device for humidifying air with water vapor

ABSTRACT

A device for humidifying air with water vapor is provided, in which water is brought to boil by means of electrical current and evaporates. Minerals or dry residue contained in the water ( 4 ), in particular, lime, become separated, and fresh water containing minerals and dry residue is also refilled approximately according to the amount of evaporated water. The minerals or dry residue, in particular, lime, are removed from the container ( 2 ) that holds the water ( 4 ) to be evaporated immediately after its formation or during the evaporation. For this purpose, the water from the container ( 2 ) is circulated in a closed external circuit, for example, with a small pump ( 9 ). The circuit has a line ( 6 ), the filter ( 7 ), and a return line ( 8 ), as well as a mixing container ( 11 ), in which the fresh water enters via a line ( 12 ), so that it is led together with the cleaned water via a common line ( 13 ) back into the container ( 2 ). In this circuit, the water is filtered mechanically and the separated lime collects outside of the container ( 2 ), so that the container does not have to or rarely needs to be cleaned. The separator or filter ( 7 ) can be flushed continuously or at time intervals.

BACKGROUND

The invention relates to a method for humidifying air with water vapor, wherein water is brought to a boil and evaporates, in particular, by means of electric current, and minerals or dry residue, in particular lime, contained in the water are separated, with fresh water containing minerals and dry residue being refilled approximately according to the amount of evaporated water, wherein, during the evaporation, a portion is diverted from the water to be boiled and evaporated, cleaned and/or filtered by separating minerals or dry residue, and then fed back to the water to be boiled and evaporated.

The invention further relates to a device for humidifying air with water vapor with, in particular, an electrically heatable container for holding the water, in which the water is brought to a boil and evaporates, wherein the container has a water inlet for refilling water according to the amount of evaporated water, wherein on the container at least one external circuit is provided with at least one line that leads to a separator or filter, which is arranged outside of the container and from which a return line leads back into the container, and wherein a downwards slope or a conveying device is provided in the line between the container and separator or filter.

So-called steam humidifiers are used in the air-conditioning industry for the purpose of humidifying the air. In such a steam humidifier, water is brought to a boil and evaporates. Here, one distinguishes essentially between two heating systems, namely those with resistance heaters and those with electrodes. Both systems function in different ways. The basic process of evaporation, however, is identical in both systems, that is, water is boiled usually under atmospheric pressure, whereby water vapor is generated.

One problem of such steam humidifiers is the separation of minerals or dry residue, in particular, of lime during operation. Here, the term “lime” is understood to be all of the solids that precipitate during the water evaporation. These can vary greatly.

Steam humidifiers with resistance heaters are preferably supplied with treated water, namely so-called softened or deionized water, because the heating system functions independent of the electrical conductivity of the water. For this processing and heating system, it is usually recommended to use treated water, so that the lime deposits can be reduced to a minimum. If, namely, tap water is used, large amounts of lime are produced, which lead to the incrustation of the heating elements. This incrustation can lead to damage and combustion of the heating rods. Here, these containers or tanks are relatively difficult to clean in terms of construction. For these reasons, the mentioned recommendation to use only treated water has already been stated.

This treatment or preparation of water, however, is complicated, because, in particular a separate, expensive preparation system is usually required for this purpose.

Steam humidifiers heated with electrodes can operate with conductive water, that is, with drinking water, which contains lime and which is hard, because the heating current between the electrodes flows directly through the water. This is the essential advantage of a steam humidifier with electrode heating. Water preparation is not necessary.

Here, such steam humidifiers to be heated by means of electrodes are usually constructed so that the container—frequently called a “cylinder”—has an economical construction and is usually made from plastic. The lime gradually collects in this container, which is replaced as a whole after a contingent operating period has elapsed. Cleaning work can be prevented through the complete replacement of the container or steam cylinder. However, the user must deal with a corresponding replacement part. Here, the service life of such a container equals about 800 to 2000 hours according to the hardness of the feed water that is used.

In addition there are embodiments, in which the container is comprised of at least two parts and can be opened for cleaning. Cleaning work on containers of steam humidifiers with electrode heating, however, is relatively complicated. The lime can collect in the container as a slurry in the form of several kilograms and must be removed and disposed of.

The deficiencies mentioned above can be counteracted with the measures according to JP 2000304311 A, because a portion is diverted from the water to be evaporated and cleaned and filtered through the separation of minerals or dry residue and then can be fed back to the water to be evaporated. In this way it can be ensured that minerals or dry residue or “lime” is separated from the water during the evaporation, instead of this “lime” precipitating in the container itself.

Through a separate inlet, the amount of evaporated water is simultaneously replaced by fresh water still containing minerals. Thus, such minerals or dry residue is introduced back into the container and at least two inlets are necessary on the container itself.

SUMMARY

Therefore, there is the objective of creating a method and a device of the type named above, in which the advantages of cleaning the water to be evaporated during the evaporation process are maintained, with which the necessity of disposing of a container or cleaning device itself can be delayed and reduced considerably or even avoided, but also simultaneously the supplied fresh water can be diluted in terms of the dry residue contained in it.

To meet this apparently contradictory objective, the method according to the invention provides that the cleaned and/or filtered water is guided into a collection container, in which the fresh water for refilling is poured, and that the cleaned and/or filtered water and the water for refilling are introduced together and/or mixed into the heated container. Thus, the fresh water still containing dry residue is already diluted before it is introduced into the container and this introduction of the fresh water into the container can also be used simultaneously for feeding the cleaned or filtered water back into the container.

Here, it is simultaneously provided that during the evaporation a portion is preferably continuously diverted from the water and is cleaned from minerals or dry residue or of “lime,” instead of this “lime” precipitating in the container itself. Simultaneously, in a known way the amount of evaporated water is replaced by fresh water still containing minerals. Therefore, as a whole the precipitation of such minerals or dry residue in the container can be prevented or at least slowed down considerably. The lime is removed from the container or cylinder practically immediately after its formation during the evaporation. Thus, manual cleaning of the container or its complete replacement can be prevented and an increased service life of this vapor container can be achieved for simultaneous reduction of the wear on all of the parts in contact with the water.

Here, it is preferable when the water diverted from the boiling water is fed to a separator or filter by means of gravity and/or by a conveying device or pump. If gravity is used, the separator or filter must be arranged lower than the branch from the container. If a conveying device or pump is used, the separator or filter can also be arranged higher than the container. Thus, as a whole a circuit for this water can be used to separate and to collect the lime or similar dry residue outside of the container, wherein mechanical separation is possible, because the lime is separated from the water during the evaporation. The external circuit for this water is closed, in that it is fed back into the container behind the cleaning or filtering point.

Here, it is preferable when the diverted water is fed from the branch at a greater height to a separator or filter located higher than the branch and is fed back into the heated container after cleaning and/or filtering, in particular, by gravity. This water can thus flow through the separator or filter and then can be led back into the container practically automatically in the accumulating amount.

The water to be cleaned and/or filtered can be diverted from the boiling water at a distance from the point, at which the refilling water and the cleaned and/or filtered water are introduced into the container. In this way, it can be prevented that a portion of the cleaned water is led back into the external circuit and to the separator or filter and thus this separation of “lime” is ineffective in the closed external circuit.

For example, the cleaned and/or filtered water and the fresh water can be filled into the container from below and the water to be cleaned and/or filtered can be diverted at a distance above this water inlet. In this way, the fact that a greater amount of heat is usually located at a greater height can also be taken into account, that is, the water is diverted and/or discharged from the container into a correspondingly hot area, where the evaporation process promotes the separation of the “lime” accordingly.

For its part, the separator or filter cleaning the diverted water can be flushed or cleaned continuously or at time intervals, wherein a flushing water supplied, if necessary, separately is forced through the separator or filter against the direction of flow of the water to be cleaned and discharged through a separate drain or wherein the flushing liquid is guided in the direction of the water to be cleaned and/or filtered into the separator or filter and the minerals or dry residue collected therein are washed away over the top or side edge of the separator or filter. The separator or filter can be flushed in reverse largely or completely automatically and the lime can be fed to a water outlet, so that an automatic, complete, and largely continuous cleaning of the container or steam cylinder is enabled.

The device according to the invention, which meets the objective, provides that between the separator or filter or a container housing the separator or filter and the heatable container, there is a collection container or mixing container, into which opens, on one side, the return line for the cleaned and/or filtered water and, on the other side, a supply line for the refilling water, and that a common line leads from the collection container to the water inlet of the heated container. Such a device allows, for a relatively simple and economic construction, the execution of the previously described method, that is, a largely continuous removal of lime or dry residue from the water to be evaporated, so that such residue cannot collect at all or only slightly in the container itself and therefore this container gains a longer service life and its complicated cleaning can be largely avoided. These considerable advantages are achieved through a simple attachable circuit line to the separator or filter, which, in practice, does not increase the production expense of the device, but simplifies the later operation and makes it considerably more cost-effective over the time period.

In the line between the container and the separator or filter, at least one pump, in particular, a hose pump, can be provided as a conveying device. This can not only suction and dose the water diverted from the container in a correspondingly good way, but can also feed this water, in particular, continuously to a separator or filter and also through these components.

Due to the device according to the invention, the fresh water for refilling can be mixed with the cleaned or filtered water and introduced with this water together into the container, so that it is already “diluted” when it is introduced into the container. Here, the pump or hose pump arranged between the container and the separator or filter also has the advantage that the amount of diverted water can be easily dosed.

For a device with a container, in which there are electrodes immersed in the water to be heated or evaporated, preferably a measurement device for the power consumption of the electrodes can be provided, which controls the amount of diverted water and the amount of water to be cleaned and/or filtered for increasing conductivity of the water in the sense that a variable amount of water can be diverted discontinuously or continuously. If the amount of water in the container decreases due to evaporation and therefore the concentration of minerals in this water increases, then the conductivity rises. This measure of the increasing conductivity can preferably be used to divert and to clean more water accordingly and also to increase the supply of fresh water accordingly.

Here, the inlet into the branch line can be arranged within the container underneath the electrodes and above the inlet for the refilling water and can have a protective filter on its inlet or in front of its inlet. Thus, impurities that could damage the pump can be kept away from the pump.

For a device with a heating rod, resistance heater, or a heating coil immersed in the water to be evaporated, the container can include level regulation via sensors for its fill height. In this way, it can also be guaranteed that the amount of evaporated water is replaced by a corresponding amount of fresh water.

The connection line from the mixing container to the container housing the water to be evaporated can open into the upper region or at the top side of the container and can have or form a siphon. Thus, the reverse feed of the cleaned water and the refilling of the fresh water can be performed at the greatest possible distance to a branch line from the container, wherein the siphon can prevent the generated vapor from escaping through the return line and the mixing container.

The branch and an additional, preferably still provided outlet from the heatable container can be arranged directed towards different sides and spaced apart from each other approximately at the same height. Thus, the container can also be emptied occasionally via the outlet even when it is not in use.

Primarily in the combination of one or more of the previously described features and measures, lime can be removed from the container or steam cylinder immediately after its formation or during the evaporation, in that the water of the container is circulated in a closed external circuit, for example, with a small pump with a pumping capacity of a few cubic centimeters per second and is filtered in this external circuit, in particular, mechanically. The lime collects in a filtering system outside of the container and not in this container itself. In this way, mechanical removal is possible, because the lime is separated during the evaporation. The water without lime can be fed back to the container together with fresh water, so that this method maintains the necessary fill height practically constantly. Manual cleaning of the container is not necessary, which reduces the maintenance costs. Simultaneously, an increased service life is produced for the container and all of the parts coming in contact with the water, because the wear is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are described in more detail below with reference to the drawings. Shown in schematic representation are:

FIG. 1 is a view of a device according to the invention for humidifying air with water vapor from a container, which can be heated electrically by means of electrodes and from which a portion of the water is diverted during the evaporation and is fed to a separator or filter in an external circuit and is fed back to the container after being cleaned together with fresh water, wherein a measurement device for the power consumption of the electrodes is provided for controlling the amount of diverted water and the amount of supplied, fresh water, and

FIG. 2 is a view corresponding to FIG. 1, in which a resistance heater is provided as an electric heating system for the water in the container and a level regulator is provided for controlling the amount of diverted water and the amount of fresh water fed into the container.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the description of the embodiments below, parts that are essentially identical in function receive the same reference symbols, even if they have different constructions.

A device designated as a whole with 1 is used for humidifying air with water vapor and has primarily an electrically heatable container 2 with an upper vapor outlet line 3. This container 2 holds water 4, which is brought to a boil and is evaporated with the help of the heating device, so that the vapor can escape through the outlet line 3. In a way still to be described, the container 2 also has a water inlet for refilling fresh water according to the amount of evaporated water, wherein the essential parts of this water inlet are a feed line 12 and a supply inlet valve 5.

In both embodiments, an external circuit is provided with a line 6, which leads to a separator or filter 7 arranged outside of the container 2, with a return line 8 leading back into the container 2 from this separator or filter, whereby this external circuit is closed. In the line 6, a downwards slope for the flow of water could be provided between the container 2 and separator or filter 7, but in both embodiments, a conveying device constructed as a pump 9, in particular, as a hose pump, is provided in this line 6. The pump 9 draws a corresponding amount of boiling water from the container 2 and feeds it to the separator or filter 7.

Thus, with both devices a portion can be diverted during the evaporation from the water 4 to be boiled and evaporated, can be cleaned and/or filtered through the separation of minerals or dry residue or lime, and can then be fed back to the water to be boiled and evaporated 4.

Here, one sees in both embodiments a collection container or mixing container 11, into which opens, on one side, the return line 8 for the cleaned or filtered water and, on the other side, the supply line 12 for the refilling water, between the separator or filter 7 or a container 10 housing the separator or filter 7 and the heatable container 2. A common line 13 leads from the collection container 11, in which the filtered water and the fresh water for refilling come together and are thus mixed, to the water inlet 14 of the heated container 2.

The water diverted from the boiling water 4 via the line 6 with the help of the pump 9 can thus be led to the separator or filter 7, wherein this diverted water is led from the branch 15, which is located in the interior of the container 2, at a greater height to a separator or filter 7 located higher than this branch and is fed back into the heated container 2 after the cleaning or filtering, for example, via gravity, wherein first, however, it is led into the collection or mixing container 11, into which the water for refilling is also filled via the supply line 12. The filtered water and the water for refilling are thus combined in this container 11 and therefore mixed and then introduced into the heated container 2 via the common line 13.

In FIG. 1, an embodiment is shown, in which the device 1 is provided with a container 2, in which electrodes 16 are provided immersed in the water 4 to be heated and evaporated. The water 4 has sufficient conductivity to produce a current flow between the two electrodes 16. Through evaporation of a portion of the water 4, the concentration of the minerals and solids in the water 4 increases, so that its conductivity rises. Therefore, in the current supply to the electrodes 16, a measurement device 17 is provided for the power consumption of the electrodes 16, which determines this increasing current flow for decreasing water level in the container 2 and controls the amount of diverted water and the amount of water to be cleaned and/or filtered for increasing conductivity of the water 4 through control electronics 18 in the sense that a greater amount of water can be diverted discontinuously or continuously. Simultaneously, the control electronics 18 can also change, for example, increase, the amount of fresh water for refilling via the inlet valve 5 into the supply line 12. Here, if the conductivity decreases too much, the control electronics 18 can also temporarily decrease the amount of water 4 within the container 2 via an outlet valve 20 in the region of the water inlet 14 or underneath this water inlet 14.

Here, the inlet into the branch line 6, that is, the actual branch 15 is arranged within the container 2 underneath the electrodes 16 and above the supply for the water for refilling, that is, above the water inlet 14. Simultaneously, one sees a large protective filter 21 at the inlet or before the inlet into the branch 15.

The water to be cleaned and/or filtered can thus be diverted from the boiling water 4 at a distance to the position, at which the water for refilling and the cleaned or filtered water are introduced into the container 2, wherein, in the embodiment according to FIG. 1, the branch 15 is arranged at a distance above the water inlet 14 accordingly.

The cleaned or filtered water and the fresh water are refilled at the bottom at the lowest point in the container 2, while the water to be cleaned and filtered is branched at a distance above this water inlet 14 or the water inlet.

In the embodiment according to FIG. 2, the device 1 has a resistance heater 26 immersed in the water 4 to be evaporated, so that the conductivity of the water 4 plays no role.

Therefore, in this embodiment the container 2 has a level regulator 22 for measuring a fill height using several sensors 23, which can display, for example, a lowest, a middle, and a highest fill height.

This level regulator or level controller 22 can interact, in turn, with control electronics 18, which control the pump 9, an inlet valve 5 in the supply line 12, and also an inlet valve 24 still to be described for the flushing of the filter 7, as well as finally the outlet valve 20 of the container 2. Thus, the level within the container 2 can be adapted to the generated amount of steam and the resulting fluid loss via a corresponding opening and closing of the valves 5, 20, and 24 and a corresponding increase or decrease in the rotational speed of the pump 9.

Here, one sees in the embodiment according to FIG. 2 that the common connection line 13 opens from the mixing container 11 to the container 2 containing the water 4 to be evaporated in the upper region or at the top side of this container 2 and has or forms a siphon 24, which prevents water vapor from escaping through this common line 13. The branch 15 and the outlet valve 20 for an outlet from the heatable container 2 lie approximately at the same height and are spaced apart from each other and directed towards opposite sides.

In the two embodiments, it is possible that the separator or filter 7 for cleaning the diverted water is flushed or cleaned continuously or at time intervals, wherein flushing water fed through a flushing line 25 is forced against the direction of flow of the water to be cleaned by the separator or filter 7 and can be drained through a separate outlet 27, as provided in both embodiments, wherein the flushing fluid is guided in the direction of the water to be cleaned and filtered into the separator or filter 7 and the minerals or dry residue collected therein are washed away over the top or side edge of the separator or filter 7 into the outlet 27. Here, one sees at the start of the flushing line 15 the already mentioned inlet valve 24 for this filter flushing. This can also be controlled by the control electronics 18.

For humidifying air with water vapor, water is brought to boil and evaporates via the electric current. Minerals or dry residue, in particular, lime, contained in the water 4, wherein fresh water containing minerals and dry residue is also refilled again approximately according to the amount of evaporated water. Here, the minerals or dry residue, in particular, lime, is removed from the container 2 containing the water 4 to be evaporated immediately after the formation or during the evaporation. For this purpose, the water of the container 2 is circulated in a closed external circuit, for example, with a small pump 9. The circuit has a line 6, the filter 7, and a return line 8, as well as a mixing container 11, in which the fresh water enters via a line 12, so that it is led back into the container 2 together with the cleaned water via a common line 13. In this circuit, the water is filtered mechanically and the separated lime collects outside of the container 2, so that this has to be cleaned not at all or only very rarely. 

1. Method for humidifying air with water vapor, the method including: boiling and evaporating water (4) using an electric current in a heated container (2), and separating minerals or dry residue contained in the water (4), refilling fresh water containing additional minerals or dry residue into the heated container approximately according to an amount of evaporated water, during the evaporation, diverting a portion from the water (4) to be boiled and evaporated, and cleaning and/or filtering the portion that is diverted through separation of minerals or dry residue, feeding back the portion of the cleaned and/or filtered water to the water (4) to be boiled and evaporated in the heated container (2), by guiding the portion of the cleaned and/or filtered water into a collection or mixing container (11), into which the fresh water for refilling is filled, and mixing the portion of the cleaned and/or filtered water and the fresh water for refilling in the collection or mixing container (11) prior to introduction into the heated container (2).
 2. Method according to claim 1, wherein the water diverted from the boiling water (4) is fed by gravity and/or by a conveying device or pump (9) to a separator or filter (7).
 3. Method according to claim 2, wherein the diverted water is led from a branch (15) at a greater height to a separator or filter (7) located higher than the branch and is fed back into the heated container (2) by gravity, after the cleaning and/or filtering.
 4. Method according to claim 1, wherein the water to be cleaned and/or filtered is diverted from the boiling water (4) at a distance to a position at which the fresh water for refilling and the cleaned and/or filtered water are introduced into the container (2).
 5. Method according to claim 1, wherein the cleaned and/or filtered water and the fresh water are filled from below into the container (2) and the water to be cleaned and/or filtered is diverted at a distance above a water inlet.
 6. Method according to claim 2, characterized in that the separator or filter (7) cleaning the diverted water is flushed or cleaned continuously or at time intervals, and separately supplied flushing water is forced against a direction of flow of the water to be cleaned through the separator or filter (7) and is discharged through a separate outlet (27) or wherein the flushing fluid is guided in a direction of the water to be cleaned and/or filtered into the separator or filter (7) and the minerals or dry residue collected therein is washed over the top or side edge of the separator or filter (7).
 7. Device (1) for humidifying air with water vapor, comprising: an electrically heatable container (2) for storing water (4), in which the water is brought to a boil and evaporates, the container (2) has a water inlet for refilling water (4) according to an amount of evaporated water, wherein on the container (2) at least one external circuit is provided with at least one line (6), which leads to a separator or filter (7) arranged outside of the container (2), from which a return line (8) leads back into the container (2), and wherein a downwards slope or a conveying device is provided in the at least one line (6) between the container (2) and the separator or filter (7), wherein between the separator or filter (7) or a container (10) housing the separator or filter (7) and the heatable container (2) there is a collection container or mixing container (11), into which open, on one side, the return line (8) for cleaned and/or filtered water and, on the other side, a supply line (12) for the water for refilling, and that a common line (13) leads from the collection container (11) to the water inlet (14) of the heatable container (2).
 8. Device according to claim 7, wherein at least one pump (9) is provided in the at least one line (6) between the container (2) and the separator or filter (7) as a conveying device.
 9. Device according to claim 8, wherein electrodes (16) are located in the container (2) to be immersed in the water (4) to be heated and evaporated, and a measurement device (17) is provided for determining a power consumption of the electrodes (16), which controls an amount of diverted water and the water to be cleaned and/or filtered for increasing conductivity of the water (4) through discontinuous or continuous diversion of a variable amount of water.
 10. Device according to claim 9, wherein the inlet into the branch line (6) is arranged within the container (2) underneath the electrodes (16) and above the supply for the water for refilling and has a protective filter (21) at an inlet or in front of the inlet thereof.
 11. Device according to claim 7, further comprising a heating rod, a resistance heater (26), or a heating coil located in the container (2) so as to be immersed in the water (4) to be evaporated, the container (2) has a level regulator (22) for determining a fill height using sensors (23).
 12. Device according to claim 7, wherein the common line (13) opens from the mixing container (11) to the container (2) which holds the water (4) to be evaporated in a top region thereof or at a top side of the container (2) and has or forms a siphon (24).
 13. Device according to claim 7, wherein the branch (15) and an outlet from the heatable container (2) are arranged at approximately the same height spaced apart from each other and directed towards different sides. 